Problem: What do the following two equations represent? $-5x-5y = -5$ $-15x-15y = 2$
Putting the first equation in $y = mx + b$ form gives: $-5x-5y = -5$ $-5y = 5x-5$ $y = -1x + 1$ Putting the second equation in $y = mx + b$ form gives: $-15x-15y = 2$ $-15y = 15x+2$ $y = -1x - \dfrac{2}{15}$ The slopes are equal, and the y-intercepts are different, so the lines are parallel.